Magnetic transcutaneous mount for external device of an associated implant

ABSTRACT

Disclosed is a transcutaneous coupling apparatus comprising a first member subcutaneously positioned in a user of the invention and also comprising a second member positioned supercutaneously, or outside the skin of the user. Rare-earth magnets are associated with the first and second members to magnetically secure the second member with the first member without significantly adversely affecting the user&#39;s skin intervening between the first and second members.

BACKGROUND OF THE INVENTION

This invention relates generally to apparatus for coupling a memberimplanted in a body with a member located outside the body. Moreparticularly, but not by way of limitation, the invention relates to abio-electronic signal coupling device (such as a hearing aid having acochlear implant unit and a sound receiving unit) utilizing rare-earthmagnets to properly align and secure an external member (such as thesound receiving unit) with an internal member (such as the cochlearimplant unit).

In the medical implantable electronic prosthesis field it is necessaryto maintain proper alignment between units implanted within the body andunits associated therewith but located externally of the body.Specifically, in medical prostheses involving electrical signaltransfers, such as hearing aids, it is critical to maintain a properalignment between the implanted and external units to insure effectivesignal transfer.

For example, a hearing aid known as an auditory neural prosthesis isused to electrically stimulate a user's auditory nerve directly orwithin the cochlea thereby to enable recognition of environmental soundsand to improve lip-reading skills. Such a prosthesis includes aninternal, subcutaneously located signal receiving unit implanted in theuser so that an electrical signal can be conducted to a cochlea of theuser. The prosthesis also includes an external sound detecting andtransmitting unit located outside the skin of the user.

For the sound detecting and transmitting unit to effectively transmit tothe receiving unit electrical signals corresponding to the detectedsounds, the sound detecting and transmitting unit must be maintained inproper alignment with the receiving unit. Presently proposed or useddevices attempt to maintain alignment by utilizing eyeglass framesspecially constructed to carry the sound detecting and transmittingunit. This frame structure has the shortcoming of permittingmisalignment between the external and internal units because theeyeglass frames can slip and otherwise become easily moved. Suchmisalignment decreases, if not totally eliminates, the amplitude of thecoupled signal received by the receiving unit. This decrease or loss ofsignal results in decreased or lost cochlea stimulation which causesfrustration in the user of the apparatus because he or she has tocontinually readjust the eyeglass frames to maintain the apparatusoperative. This misalignment also hampers the training, evaluation anduse of the prosthesis user.

If the eyeglass frame structure were used with multichannel auditoryneural prostheses which are being developed to provide frequency codingof detected sounds, the reliability of such multi-channel devices wouldbe greatly decreased because accurate alignment is critical to insurethat each of the plurality of signals transmitted by the transmittermeans in the multi-channel transmitter unit is received by the properreceiver means in the implanted multi-channel receiving unit.

Although proper alignment must be maintained in medical apparatus havingunits located both beneath the surface of the skin and above the skin,it is desirable that there be no mechanical connection which extendsthrough the skin of the user between the internal and external units.Although no mechanical connection, which could rigidly maintain apredetermined distance between the internal and external units so thatno compression of the intervening skin occurred, is wanted, neither isthere desired a coupling device which adversely affects, such as bycompression, the skin extending between the implanted unit and theexternal unit. Therefore, what is desired is an apparatus which securesthe external unit with the internal unit without adversely affecting theintervening tissue.

Although there have been proposed and made medical apparatus havingimplantable units and external units which need to be coupled or held inalignment by some means, such as the aforementioned type of hearing aidusing an eyeglass frame, we do not know of any such apparatus whichdiscloses or suggests our invention as disclosed and claimedhereinbelow.

SUMMARY OF THE INVENTION

The present invention overcomes the above-noted and other shortcomingsof the prior art by providing a novel and improved medical apparatuscoupling device. This apparatus maintains in proper alignment or desiredpositional securement a unit which is disposed beneath the surface ofthe skin of a user and a unit located outside the surface of the user'sskin. Furthermore, there is no mechanical connection extending throughthe user's skin to maintain this alignment. Additionally, this presentinvention has no known significantly adverse effect on the user's skinextending between the internally located unit and the externallypositioned unit.

Broadly, the present invention provides a transcutaneous couplingapparatus comprising a first member positioned subcutaneously, a secondmember positioned supercutaneously (i.e., outside the skin), and magnetmeans for magnetically securing the second member to the first member.

The first member includes in preferred embodiments electronic meanswhich can receive an electrical signal or transmit an electrical signalor perform both functions. Likewise, the second member includes in afirst embodiment means for transmitting the electrical signal to thereceiving first member or in another embodiment includes electronicmeans for receiving the electronic signal transmitted by the firstmember. Alternatively, the second member can include means forperforming both receiving and transmitting functions.

When the first and second members specifically include receiving andtransmitting means, respectively, the transcutaneous coupling apparatusis a bio-electronic signal coupling device for maintaining a desiredpositional relationship between the first and second members so that theproper transmitting and receiving between the members can occur. In suchan embodiment the first member specifically includes a firstelectrically conductive coil having two ends, each of which is embeddedin tissue of the user of the apparatus. The second member in such anembodiment includes a second electrically conductive coil and signalgenerating means, electrically connected to the second coil, forproviding an electrical signal to the second coil so that the signal istransferred by electromagnetic induction transcutaneously to the firstcoil for electrically stimulating the tissue in which the ends of thefirst coil are embedded.

The magnet means generally includes a rare-earth element. Moreparticularly, the magnet means includes a first rare-earth magnetassociated with the first coil of an embodiment of the first member, andthe magnet means also includes a second rare-earth magnet associatedwith the second coil of an embodiment of the second member, formagnetically coupling with the first rare-earth magnet so that the firstand second coils are positioned to achieve electromagnetically inductivecoupling. To maintain the first and second members in a predeterminedrelation, the magnet means further includes a third rare-earth magnetassociated with the first coil and a fourth rare-earth magnet,associated with the second coil, for magnetically coupling with thethird rare-earth magnet. To achieve the predetermined alignment, thethird and fourth magnets have as their attractive polarities magneticpoles of opposite polarities to the attractive polarities of the firstand second magnets so that each of the magnets on the first member willbe attracted to only one of the magnets located on the second member.

From the foregoing it is a general object of the present invention toprovide a novel and improved medical apparatus coupling device. Otherand further objects, features and advantages of the present inventionwill be readily apparent to those skilled in the art when the followingdescription of the preferred embodiments is read in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration and block diagram of a preferredembodiment of the present invention.

FIG. 2 is a sectional side elevational view of a coil assembly of thepreferred embodiment of the present invention.

FIG. 3 is an end elevational view of the coil assembly shown in FIG. 2.

FIG. 4 is a schematic and block diagram of the electronic elements ofthe preferred embodiment of the present invention.

FIG. 5 is a sectional side elevational view of a coil assembly of asecond preferred embodiment of the present invention.

.Iadd.FIG. 6 is a block diagram of another preferred embodiment of thepresent invention. .Iaddend.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The medical apparatus coupling device of the present invention providestranscutaneous coupling of a subcutaneously located first member with asupercutaneously (i.e., outside the skin) positioned second member. Todescribe this invention, specific reference will be made to preferredembodiments of a bio-electronic signal coupling device which assists thehearing of a user of the device. The signal coupling device isparticularly a hearing aid 2 schematically illustrated by the blockdiagram shown in FIG. 1.

The hearing aid 2 includes an internal first member 4 which isdesignated in FIG. 1 as an internal coil assembly 6. In the preferredembodiment the internal coil assembly 6 is a cochlear implant unitcontaining electronic receiver means for receiving a transmitted signal.However, it is to be noted that in other embodiments the internal coilassembly 6 can include means for transmitting a signal or means for bothreceiving and transmitting signals. .Iadd.See, for example, transmitter48 depicted in FIG. 6. .Iaddend.Units other than signal receiving ortransmitting ones can also comprise the first member.

The internal coil assembly 6 is subcutaneously located beneath a layerof tissue 8 which includes the epidermal and dermal layers of the skinof the user of the device when the device is the preferred embodimenthearing aid 2. FIGS. 2 and 4 disclose that the internal coil assembly 6includes a first electrically conductive coil 10 of wire having two endsembedded in subcutaneous tissue. Specifically, as shown in FIG. 4 afirst end or electrode 12 of the coil 10 is inserted in a cochlea of theuser and a second end or electrode 14 is inserted in adjacent tissue asa reference electrode. In the preferred embodiment the first coil 10comprises six hundred turns of 40 AWG copper wire. This wire is wound ona first support member 16 comprising a delrin bobbin 18 placed in aceramic, pot-type core-half 20. The core-half 20 preferably has a rightcircular cylindrical shape because a hole having a complementary shapecan be readily cut with a circular trephine into the bone in which theinternal core assembly 6 is to be inserted.

In addition to the first member 4, the present invention includes asecond member 22 which in the preferred embodiment includes signalgenerating and transmitting means 24 located supercutaneously of theuser of the invention. FIG. 1 reveals the means 24 includes a sounddetector and signal conditioner means 26 and an external coil assembly28. .Iadd.In the preferred embodiment depicted in FIG. 6, the secondmember includes a receiver 50. .Iaddend.

The external coil assembly 28 includes a second electrically conductivecoil 29. In the preferred embodiment the second coil 29 includes fourhundred turns of 38 AWG copper wire wound on a second support membercomprising a delrin bobbin and a ceramic, pot-type core-half similar tothe bobbin 18 and core-half 20 shown in FIG. 2 constituting the internalcoil assembly 6.

The sound detector and signal conditioner 26 is electrically connectedto the second electrically conductive coil 29 and generates anelectrical signal which is electromagnetically transferredtranscutaneously by the second coil 29 to the first coil 10 forelectrically stimulating the subcutaneous tissue (specifically, thecochlea) in which the electrodes 12 and 14 of the first coil 10 areembedded. FIG. 4 shows the sound detector and signal conditioner means26 includes a transducer, specifically a microphone 30, for detecting asound and converting it into a proportional electrical signal. Theproportional electrical signal is amplified by amplifier means 32 andinput into amplitude modulation circuit means 34. The amplitudemodulation circuit means 34 utilizes the amplified electrical signal tomodulate a carrier signal which is generated by carrier frequencygenerator means 36. In the preferred embodiment the carrier frequencygenerator means 36 provides a 16 kHz carrier signal which is amplitudemodulated by the electrical signal coming from the amplifier means 32.The resultant amplitude modulated signal is provided to the second coil29 for electromagnetic transmission transcutaneously through theintervening tissue 8 to the first coil 10. The microphone 30, amplifiermeans 32, amplitude modulation circuit means 34 and carrier frequencygenerator means 36 depicted in FIG. 4 are of the type as are known inthe art.

For the electromagnetically inductive transmission between the firstcoil 10 and the second coil 29 to be properly achieved, it is necessaryto provide means for properly securing the external coil assembly 28(and the sound detector and signal conditioner means 26 if it isunistructurally combined with the external coil assembly 28) with theinternal assembly 6 without significantly adversely affecting theintervening tissue 8. This is achieved in the present invention withmagnet means for magnetically securing the second member 22 with thefirst member 4. The magnet means electromagnetically associates thereceiver means provided by the preferred embodiment internal coilassembly 6 with the transmitter means provided by the preferredembodiment means 24 so that the first coil 10 of the receiver means isresponsive to the transmitted electrical signal transmitted by thesecond coil 29 of the preferred embodiment transmitter means. .Iadd.Forthe FIG. 6 embodiment, the magnet means, comprising two magnets 52, 54,magnetically secures the transmitter 48 and the receiver 50. .Iaddend.

In the preferred embodiment receiver means or internal coil assembly 6shown in FIG. 2 the magnet means include a rare-earth element which isparticularly a first rare-earth magnet 38 associated with the first coil10 by being concentrically positioned therewith in the pot-typecore-half 20. The rare-earth element included within the magnet meansmay be any appropriate one of the group of chemical elements includingatomic numbers between 58 and 71. In the preferred embodiment therare-earth element is samarium which is combined with cobalt to providea samarium-cobalt magnet (e.g., SmCo₅) having a long magnetic stabilityand a large maximum energy product.

In addition to the first rare-earth magnet 38 forming a part of themagnet means of the present invention, there is a second rare-earthmagnet associated with the second coil 29 of the second member 22 formagnetically coupling with the first rare-earth magnet 38 so that thefirst and second coils 10 and 29 are positioned for electromagneticallyinductive coupling. The magnetic coupling arises by placing attractivepoles of the first and second magnets toward each other so that themagnetic lines of force extend through the intervening tissue 8 toretain the internal and external coil assemblies in alignment adjacentthe intervening skin. For example, the magnetic north pole of the firstrare-earth magnet 38 can be positioned within the first member 4(specifically, within the core-half 20) so that it lies closer to thesecond member 22 (specifically, the core-half of the external coilassembly 28) than does the magnetic south pole of the first magnet 38.This positioning of the first magnet 38 requires that the magnetic southpole of the second rare-earth magnet be positioned in the second member22 so that it will magnetically couple with the magnetic north pole ofthe first magnet when the second member 22 is placed to properlyposition the second coil 29 relative to the first coil 10.

To use the preferred embodiment of the present invention depicted inFIGS. 1-4, the first member 4 containing the first rare-earth magnet 38is subcutaneously implanted in the user of the apparatus. Duringimplantation the electrodes 12 and 14 of the first coil 10 are implantedin the respective locations previously described. Next, the secondmember 22, having the second rare-earth magnet associated therewith, ispositioned supercutaneously adjacent the outer surface of the user'sskin so that the first and second magnets magnetically secure themselvestogether thereby properly positioning the first and second coils 10 and29 for maximum signal transference from the second member 22 to thefirst member 4.

The signal which is to be transferred from the second member 22 to thefirst member 4 is obtained by using the transducer or microphone 30 todetect an ambient sound and converting it into a proportional electricalsignal, amplifying this signal, and amplitude modulating with thisamplified signal the 16 kHz carrier signal generated by the carrierfrequency generator means 36. The amplitude modulated signal istransferred to the second coil 29 of the second member 22 forelectromagnetically inductive coupling with the first coil 10 of thefirst member 4. The electromagnetically induced signal received by thefirst coil 10 is impressed across the reference tissue and cochleatissue to which the electrodes of the first coil are embedded. Thiselectrical stimulation of the cochlea enhances the hearing andlip-reading skills of the user.

The previously described type of system utilizing the single first coil10 and the single second coil 29 is known as a single-channel hearingaid because only a single signal is transferred to the user of theapparatus at any one time. However, there are multi-channel deviceswhich are being developed for simultaneously transferring a plurality ofsignals to permit frequency coding and subsequent frequency analysis ofthe detected sounds. To insure the proper operation of suchmulti-channel devices, it is necessary to accurately align therespective transmitting and receiving channels comprising, for example,a plurality of coils similar to those shown in the drawings. The initialalignment and subsequent maintenance of the alignment would be difficultusing the preferred embodiment shown in FIGS. 1--4 because with only asingle pair of magnets, the first member and second members could rotatewhereby respective channels could become misaligned. To preventmisalignment, a plurality of magnets forming a multiple number of magnetpairs can be used as shown in a second preferred embodiment illustratedin FIG. 5. It is to be noted that although the FIG. 5 embodiment is ofthe single-channel type, it could readily be adapted to a multi-channeltype.

The FIG. 5 embodiment discloses a support member 40 and coil assembly 42similar to that shown in FIGS. 2 and 3. However, the magnet means of theFIG. 5 embodiment is different from that shown in FIG. 2 because tworare-earth magnets are disposed in the support member 40 of FIG. 5. Afirst rare-earth magnet 44 is magnetically coupled with a secondrare-earth magnet (not shown) which is properly situated in a secondmember which is similar to the second member 22. A third rare-earthmagnet 46 shown in FIG. 5 is paired with a fourth rare-earth magnet (notshown) which is properly situated in the second member of the secondpreferred embodiment. Therefore, the magnets are grouped in attractivemagnetic relation between the receiver and transmitter means of thefirst and second members, respectively.

It is apparent that through the use of the plurality of magnets depictedin FIG. 5, misalignment is less likely to occur once the first andsecond members are magnetically coupled. However, it is sometimesnecessary to orient the first member with respect to the second memberin a single, predetermined alignment.

If the two magnets of the first member shown in FIG. 5 has the samepolarity orientation and the two magnets of the second member had thesame polarity orientation as between themselves but opposite that of themagnets of the first member, the second member could be magneticallycoupled to the first member in either of two directions. For example, ifeach of the magnets 44 and 46 shown in FIG. 5 has its magnetic northpole facing the second member and each of the magnets in the secondmember had its magnetic south pole facing the first member, the firstand second members could be positively related so that either the firstand second magnets and the third and fourth magnets were magneticallycoupled or the first and fourth magnets and the second and third magnetswere magnetically coupled.

To restrict the alignment between the first and second members to asingle predetermined position, the first and third rare-earth magnets 44and 46 can be disposed in the first member so that the two polaritiesfacing the second member are opposite. For example, the first magnetcould have its magnetic north pole disposed for coupling with the secondmember and the third magnet could have its magnetic south pole disposedfor coupling with the second member. To complement this pole placement,the second magnet could be disposed in the second member so that itsmagnetic south pole is disposed for coupling with the first member andthe third magnet could be disposed in the second member so that itsmagnetic north pole is disposed for coupling with the first member. Withsuch magnetic polarities positioned for coupling the first and secondmembers, the first and second members can only be magnetically coupledin a single alignment because coupling will occur only when the firstmagnet and second magnet are aligned and the third magnet and fourthmagnet are aligned. The reverse alignment of the magnets of the firstand second members results in similar poles facing each other therebycausing a repulsive force. This can be more generally stated by sayingthat the third and fourth magnets have as their attractive polaritiesmagnetic poles of opposite polarities to the attractive polarities ofthe first and second magnets, respectively.

Although the specific embodiments described above disclose either asingle pair of magnetic slugs in the shape of small disks located in thecenters of symmetrical pot-type core halves or two such pairs ofmagnetic slugs, it is to be noted that other configurations are alsofeasible. For example, a ring magnet disposed along the periphery of thepot-type core-half could be used. Likewise, three disk-shaped magnetscould be spaced at 120° intervals around each of the first and secondmembers. Still further, a single magnet could be disposed in either theinternal member or the external member and a magnetically attractivematerial, such as a ferromagnetic material, could be placed in the othermember so that the attractive material is held in alignment by thesingle magnet. Other forms of magnet means can likewise be used and yetremain within the scope of the present invention.

It is also to be noted that although the preferred embodiment of thepresent invention was described with reference to a bio-electronicsignal coupling device (more particularly, a hearing aid), the presentinvention contemplates any medical apparatus having a first memberimplanted below the surface of the skin of the user and having a secondmember located externally to the user's skin but transcutaneouslycoupled to the first member.

Still further, it is to be noted that the term "hearing aid" as usedherein is not limited to those devices which amplify sounds, but ratheris intended to encompass all suitable devices which assist one inhearing and/or comprehending sound.

Thus, the present invention of a medical apparatus coupling device iswell adapted to carry out the objects and attain the ends and advantagesmentioned above as well as those inherent therein. While preferredembodiments of the invention have been described for the purpose of thisdisclosure, numerous changes in the construction and arrangement ofparts can be made by those skilled in the art, which changes areencompassed within the spirit of this invention as defined by theappended claims.

What is claimed is: .[.1. A transcutaneous coupling apparatus,comprising: means includes a rare-earth element..].
 3. .[.An apparatusas defined in claim 1, wherein:said first member includes electronicmeans for receiving an electrical signal; and.]..Iadd.A transcutaneouscoupling apparatus, comprising: a first member positionedsubcutaneously; a second member positioned supercutaneously; and magnetmeans, cooperating with said first and second members, for magneticallysecuring said second member to said first member; and wherein .Iaddend.said second member includes electronic means for .[.transmitting theelectrical signal.]. .Iadd.generating an electromagnetic transmission toactivate electrical conduction in said first member; and said firstmember includes electronic means, responsive to said electromagnetictransmission, for electrically stimulating subcutaneous tissue.Iaddend..4. An apparatus as defined in claim 3, wherein said magnet meansincludes a rare-earth element.
 5. .[.An apparatus as defined in claim 1,wherein:.]. .Iadd.A transcutaneous coupling apparatus, comprising:afirst member positioned subcutaneously; a second member positionedsupercutaneously; and magnet means, cooperating with said first andsecond members, for magnetically securing said second member to saidfirst member; and wherein .Iaddend. said first member includeselectronic means for .[.transmitting an electrical signal.]..Iadd.generating an electromagnetic transmission to activate electricalconduction in said second member.Iaddend.; and said second memberincludes electronic means .[.for receiving the electrical signal.]..Iadd., responsive to said electromagnetic transmission, for conductingan electrical signal.Iaddend..
 6. An apparatus as defined in claim 5,wherein said magnet means includes a rare-earth element.
 7. .[.Anapparatus as defined in claim 1, wherein:.]. .Iadd.A transcutaneouscoupling apparatus, comprising:a first member positioned subcutaneously;a second member positioned supercutaneously; and magnet means formagnetically securing said second member to said first member; andwherein .Iaddend. said transcutaneous coupling apparatus is abio-electronic signal coupling device; said first member includes:afirst electrically conductive coil having two ends, each of said twoends being embedded in subcutaneous tissue; and said second memberincludes:a second electrically conductive coil; and signal generatingmeans, electrically connected to said second coil, for providing anelectrical signal to said second coil so that said signal iselectromagnetically transferred transcutaneously to said first coil forelectrically stimulating the subcutaneous tissue.
 8. An apparatus asdefined in claim 7, wherein said magnet means includes a rare-earthelement.
 9. An apparatus as defined in claim 7, wherein said magnetmeans includes:a first rare-earth magnet associated with said firstcoil; and a second rare-earth magnet, associated with said second coil,for magnetically coupling with said first rare-earth magnet so that saidfirst and second coils are positioned to achieve electromagneticallyinductive coupling.
 10. An apparatus as defined in claim 9, wherein saidmagnet means further includes:a third rear-earth magnet associated withsaid first coil; and a fourth rare-earth magnet, associated with saidsecond coil, for magnetically coupling with said third rare-earthmagnet, said third and fourth magnets having as their attractivepolarities magnetic poles of opposite polarities to the attractivepolarities of said first and second magnets, respectively.
 11. A hearing.[.air.]. .Iadd.aid.Iaddend., comprising:sound detector means fordetecting sound and converting it into an electrical signal; transmittermeans, positioned on the ouside of the skin of a user of said hearingaid, for transmitting the electrical signal; receiver means, positionedbeneath the skin of the user, for receiving the transmitted electricalsignal .Iadd.and for conducting said signal into tissue beneath the skinof the user.Iaddend.; and magnet means for coupling said transmittermeans with said receiver means.Iadd., .Iaddend..[.so that.]. .Iadd.with.Iaddend.said transmitter means and said receiver means .[.are.]. onopposite sides of the surface of the skin of the user.Iadd., so thatelectrical conduction is activated in said receiver means and from saidreceiver means into tissue beneath the skin of the user in response tosaid transmitter means transmitting the electrical signal.Iaddend.. 12.A hearing aid as defined in claim 11, wherein said magnet means includesa rare-earth element.
 13. .[.A hearing aid as defined in claim 12,wherein:.]. .Iadd.A hearing aid, comprising:sound detector means fordetecting sound and converting it into an electrical signal; transmittermeans, positioned on the outside of the skin of a user of said hearingaid, for transmitting the electrical signal; receiver means, positionedbeneath the skin of the user, for receiving the transmitted electricalsignal; magnet means for coupling said transmitter means with saidreceiver means so that said transmitter means and said receiver meansare on opposite sides of the surface of the skin of the user; andwherein: said magnet means includes a rare-earth element; .Iaddend. saidreceiver means includes a first electrically conductive coil; saidtransmitter means includes a second electrically conductive coil, saidfirst and second coils being electromagnetically associated by saidmagnet means so that said first coil is responsive to the transmittedelectrical signal.
 14. A hearing aid as defined in claim 13, whereinsaid first coil includes an end embedded in a cochlea of the user.
 15. Ahearing aid as defined in claim 14, wherein said sound detector meansincludes:transducer means for receiving a sound and converting it to aproportional electrical signal; amplifier means for amplifying theproportional electrical signal; carrier generator means for generating acarrier electrical signal; and amplitude modulation means, responsive tosaid amplifier means, for modulating the amplitude of the carrierelectrical signal and for transferring the modulated carrier electricalsignal to said second coil.
 6. A hearing aid as defined in claim 15,wherein:said receiver means further includes a first support memberhaving said first coil associated therewith; said transmitter meansfurther includes a second support member having said second coilassociated therewith; and said magnet means includes:a first rare-earthmagnet associated with said first support member so that a firstpolarity of said first magnet is positioned closer to said transmittermeans than is a second polarity thereof; and a second rare-earth magnetassociated with said second support member so that a polarity thereofattractive to the first polarity of said first rare-earth magnet ispositioned closer to said first magnet than is a non-attractive polaritythereof.
 17. A hearing aid as defined in claim 11, wherein said magnetmeans includes a plurality of rare-earth magnets, each of said magnetsbeing associated with a respective one of said transmitter means andsaid receiver means and being grouped in attractive magnetic relationwith another one of said magnets associated with the other of saidtransmitter means and said receiver means so that said transmitter meansand said receiver means are magnetically coupled in a predeterminedalignment.
 18. A hearing aid, comprising:sound detector means fordetecting sound and for converting it into an electrical signal; a firstelectrically conductive coil having a first end embedded in the bodytissue of a user of said hearing aid and having a second end embedded ina cochlea of the user; a second electrically conductive coil connectedto said sound detector means and positioned outside the skin of theuser; a first rare-earth magnet associated with said first coil; and asecond rare-earth magnet, associated with said second coil, formagnetically coupling with said first rare-earth magnet so that saidfirst and second coils are positioned to achieve electromagneticallyinductive coupling.
 19. A hearing aid as defined in claim 18, furthercomprising:a third rare-earth magnet associated with said first coil;and a fourth rare-earth magnet, associated with said second coil, formagnetically coupling with said third rare-earth magnet, said third andfourth magnets having as their attractive polarities magnetic poles ofopposite polarities to the attractive polarities of said first andsecond magnets, respectively.
 20. A method of .[.transcutaneously.].coupling .[.an.]. .Iadd.a transcutaneous .Iaddend.apparatus having animplantable .Iadd.electrical .Iaddend.member and an external.Iadd.electrical .Iaddend.member, comprising the steps of:associating afirst rare-earth magnet with the implantable .Iadd.electrical.Iaddend.member; associating a second rare-earth magnet with theexternal .Iadd.electrical .Iaddend.member; subcutaneously implanting theimplantable .Iadd.electrical .Iaddend.member with the associated firstrare-earth magnet; and supercutaneously positioning the external.Iadd.electrical .Iaddend.member and associated second rare-earth magnet.[.so that.]. .Iadd.for magnetically securing .Iaddend.the secondrare-earth magnet .[.is magnetically secured.]. with the firstrare-earth magnet .Iadd.so that electrical conduction occurs within theimplantable electrical member and electrical stimulation of subcutaneoustissue results therefrom in response to electromagnetic transmissionfrom the external electrical member to the implantable electricalmember.Iaddend..
 21. A method as defined in claim 20, further comprisingthe steps of:associating, prior to the step of subcutaneously implantingthe implantable .Iadd.electrical .Iaddend.member, a third rare-earthmagnet with the implantable .Iadd.electrical .Iaddend.member in opposingmagnetic polarity relation with the first rare-earth magnet; andassociating a fourth rare-earth magnet with the external.Iadd.electrical .Iaddend.member in opposing magnetic polarity relationwith the second rare-earth magnet so that the fourth rare-earth magnetis magnetically secured with the third rare-earth magnet during the stepof supercutaneously positioning the external .Iadd.electrical.Iaddend.member and so that the external .Iadd.electrical.Iaddend.member and the implanted .Iadd.electrical .Iaddend.member arecoupled in a predetermined relation.